1) (5x+(x+y))(5x-(x+y))
2) (10-(3a+7y))(10+(3a+7y))
4)(a^2-b^2)(a^2+b^2)
5) (a^3-b^3)(a^3+b^3)
6) (a^4-b^4)(a^4+b^4)
B1=8
q=1/2
S6=(b1(q^n-1))/(q-1)=(8(1/64-1))/(1/2-1)=(8(-63/64))/(-1/2)=63/8 *2=63/4=15.75
100-q²=(10-q)(10+q)
196p²-r²=(14p-r)(14p+r)
25x²-289y²=(5x-17y)(5x+17y)
a²b^4-9c²=(ab²-3c)(ab²+3c)
(m-1)²-121=(m-1-11)(m-1+11)=(m-12)(m+10)